Question: Simplify the following expression: $y = \dfrac{40k^3}{-130k^2}$ You can assume $k \neq 0$.
Explanation: Find the greatest common factor of the numerator and denominator. The numerator can be factored: $40k^3 = (2\cdot2\cdot2\cdot5 \cdot k \cdot k \cdot k)$ The denominator can be factored: $-130k^2 = - (2\cdot5\cdot13 \cdot k \cdot k)$ The greatest common factor of all the terms is $10k^2$ Factoring out $10k^2$ gives us: $y = \dfrac{(10k^2)(4k)}{(10k^2)(-13)}$ Dividing both the numerator and denominator by $10k^2$ gives: $y = \dfrac{4k}{-13}$